1. Field of the Invention
The present invention relates to an image sensor incorporated into an electronic machine such as a facsimile machine, a copying machine or an optical character reader.
2. Description of the Related Art
A conventional image sensor is generally composed of a transparent cover attached to the upper portion of a frame so as to bring the surface of the cover into contact with the object of imaging, the frame encasing a light-emitting portion for projecting light onto the object, an optical system for converging the light reflected from the object and a light-receiving portion for receiving the light from the optical system. The light-emitting portion and the light-receiving portions are provided on the respective substrates, and these substrates are fixed to the frame.
Methods of attaching such an image sensor to an electronic machine such as a facsimile machine or a copying machine are roughly classified into the two methods shown in FIGS. 5 and 6. In the method shown in FIG. 5, threaded holes 41a, 41b are formed in both longitudinal side surfaces of a frame 41 of an image sensor 40 having a transparent cover (glass cover) 42, and two L-shaped plate members 50, 51 are provided at the mounting portion of the electronic machine to which the image sensor 40 is attached. Holes 50a, 51a, and 50b, 51b which correspond to the threaded holes 41aand 41b, respectively, are formed in the plate members 50 and 51, respectively. Screws 52, 54 and 53, 55 are passed through the holes 50a, 50b, and 51a, 51b so as to be engaged with the threaded Roles 41a and 41b, respectively. Both end surfaces of the image sensor 40 are thus sandwiched between the plate members 50 and 51, and in this state the image sensor 40 is fixed to the electronic machine.
In the method shown in FIG. 6, two threaded holes 61a, 61b are formed in both side surfaces of a frame 61 of an image sensor having a glass cover 62, and two L-shaped plate members 70, 71 are provided at the mounting portion of the electronic machine to which the image sensor 60 is attached. Holes 70a, 71a, and 70b, 71b which correspond to the threaded holes 61a and 61b, respectively, are formed in the plate members 70 and 71, respectively. Screws 72, 74, 73 and 75 (not shown) are passed through the holes 70a, 71a, and 70b, 71b so as to be engaged with the threaded holes 61a and 61b, respectively. Both side surfaces of the image sensor 60 are thus sandwiched between the plate members 70 and 71, and in this state the image sensor 60 is fixed to the electronic machine.
In both of the methods shown in FIG. 5 and 6, it is necessary to form the threaded holes in the frame of the image sensor. This machining cost is very high. In addition, since it is necessary to pass the screws first into the plate members and thereafter engage them with the threaded holes of the frame when the image sensor is attached to the electronic machine, attachment of the image sensor to the electronic machine is time and labor intensive.